There is clearly a need for a soft and resilient denture lining material which can be permanently bonded to the tissue-contacting surfaces of acrylic dentures. The objective of this investigation is to evaluate selected commercial elastomers as soft liners when used in traditional and novel processing procedures. The materials chosen are commercially available in a wide range of physical properties and are readily molded. They are 1) phosphonitrilic fluoroelastomer, (PNF-200), a polymer with an a P double bond N backbone available from Firestone, 2) a butadiene/styrene/butadiene tri-block copolymer (Kraton 1107) from Shell Chemical, and 3) a modified chlorinated polyethylene (CPE-3615) from Dow Chemical. Bonding to PMMA/MMA dough yielded good results for Kraton (greater than 490 kPa or 5 kgf/sq. cm), and more recent samples have been bonded better by priming with styrene monomer. PNF bonding measured 686 kPa after priming with acetone, and CPE yielded 1960 kPa without any presoftening. The Shore A hardness of PNF and Kraton was 40; CPE measured 55 but softening methods are being investigated. Fluid absorption tests were run with distilled water, 50 percent ethanol, and 5 percent acetic acid and showed that the three elastomers gained only 1 to 2 percent in weight. All three elastomers have chemical, mechanical, and processing advantages using traditional dental lab techniques. Further development is planned. Mycobacterial tests indicate that all three elastomers neither support nor inhibit the growth of fungus. Microwave curing has been attempted to selectively head the PNF elastomer at higher temperatures.